We are not yet sure that viruses are non-living. In the present they are situated at the border between living and non-living. Also, as it was said, they interact directly with the living world and are thus, in a way, a part of it

"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

ok forget why bot lets think about what they do.....
they inject genetic material into cells, the cell then replicates the virus, but with current technology we can tamper with the genetic coding of the virus. thus with enough genetic knowledge we could engineer HELPFUL viral strains, or ones that cause cancer.
now that can give u a cold feeling deep down inside, cancer as a communicable disease

knowledge gives us the right to make opinoins.
the opinoins of a fool are worthless, and make those that hear them foolish.

ccljboy wrote:now that can give u a cold feeling deep down inside, cancer as a communicable disease

They exist already. The first one was discovered in 1910, even before virus were known. It is the chicken Sarcoma or Rous Sarcoma. 6 Viruses are known for human [Epstein-Barr Virus, Hepatits B and C viruses, papillomavirus,HHV8 (Kaposi sarcoma),HTLV].

But the question was why viruses were studied in biology, although not living strictly speaking. The answer being as it is said because they interact with living beings. And furthermore are depending on living organisms for their reproduction. So they do belong to biology who study life but also what is related to it (just like pharmacology is often considered as a part of biology although dealing with chemicals).

Even though viruses still between the border of living and not-living things, they have discovered their familia, genus and species... And, we study viruses in Biology because of the definition of the virus.
"Virus is the smallest infectius unit of the living thing"

Q: Why are chemists great for solving problems?
A: They have all the solutions.

I've heard viroids...these things are just seemed like viruses but lacks some viruses characteristics...
Yup, they had determined it like Pox viridae (suffix -dae is used to ddetermine family) and adenovirus (suffix -virus is used to determine species)

Q: Why are chemists great for solving problems?
A: They have all the solutions.

I think they are living as they interact whith living world. And also why biology study them is...they reproduce as reproduce every living thing on the world - transcription, translation of genetic information, replication... that simply belongs under genetics, molecular biology and biochemistry. Or should they be studied by mineralogy for example?

When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth. (Sherlock Holmes)